Accessing representational state transfer application programming interfaces using simple mail transfer protocol

ABSTRACT

A Representational State Transfer (REST)-Simple Message Transfer Protocol (SMTP) protocol gateway (RSPG) is disclosed that includes capabilities for accessing and processing REST Application Programming Interfaces (APIs) using SMTP. The RSPG receives a first email message, extracts information from the received first email message and constructs a REST API call based on the extracted information. The RSPG invokes the REST API call against a REST endpoint and receives a response generated from execution of the REST API call. The RSPG generates a second email message based on the response and causes the second email message to be communicated to an intended recipient of the response of the REST API call.

BACKGROUND

A Representational State Transfer (REST) Application ProgrammingInterface (API) (also known as a RESTful API) is a type of API thatenables users to interact with web services to access and retrieveresources. Traditionally, a REST API uses Hyper Text Transfer Protocol(HTTP) operations to access and retrieve data. A number of proprietarysolutions (e.g., REST clients) currently exist that facilitate theaccess and execution of REST APIs using HTTP operations such as read,update, create and delete operations. However these solutions typicallyhave to contend with the inherent deficiencies of HTTP, such asrequiring synchronous and directed (unicast) transactions, as well as acustom client to compose and process a request and response to and froma destination endpoint. There is thus a need for making the processingand execution of REST APIs more flexible than is possible in existingimplementations.

BRIEF SUMMARY

The present disclosure relates to techniques for accessing andprocessing Representational State Transfer (REST) ApplicationProgramming Interfaces (APIs) using Simple Message Transfer Protocol(SMTP). More particularly, the present disclosure relates to a REST-SMTPprotocol gateway (RSPG) that includes capabilities for receiving anemail message composed according to SMTP semantics, converting the emailmessage into a traditional REST API call for execution at an endpoint,representing the results of execution of the REST API call using SMTPsemantics and transmitting the results of execution to a sender or toalternative recipients of the email message.

In certain embodiments, an RSPG is disclosed. The RSPG extractsinformation from one or more data fields of a first email message andconstructs a REST API call based on the extracted information. The RSPGinvokes the REST API call against a REST endpoint and receives aresponse generated from execution of the REST API call. The RSPGgenerates a second email message based on the response and causes thesecond email message to be communicated to an intended recipient of theresponse of the REST API call.

In certain examples, the RSPG is configured to extract information froma To field of the first email message. Extracting information from theTo field comprises extracting information identifying the REST endpointfrom a Username portion of the To field of the first email message.Extracting information from the To field further comprises extractinginformation identifying the RSPG for accepting the first email messagefrom a Domain Name portion of the To field of the first email message.

In certain examples, the RSPG is configured to extract information froma Subject field of the first email message. Extracting information fromthe Subject field comprises extracting information identifying an actionto be performed by the REST API call and extracting informationidentifying a pathname that uniquely identifies a resource to beaccessed by the REST API call at the REST endpoint.

In certain examples, the RSPG is configured to extract additionalinformation identifying the action to be performed by the REST API callfrom the body of the email message.

In certain examples, the response generated from execution of the RESTAPI call comprises a response status code indicating that the REST APIcall was successfully executed by the REST endpoint. In certainexamples, the response generated from execution of the REST API callcomprises a response status code indicating that the REST API callfailed to successfully execute at the REST endpoint. In certainexamples, the response generated from execution of the REST API callcomprises an intermediate response status code indicating that the RESTAPI call is still being processed.

In certain examples, the RSPG is configured to determine that theresponse was not received from execution of the REST API call by theREST endpoint within a threshold period of time and responsive to thedetermining, the RSPG is configured to re-invoke the REST API call tothe REST endpoint. In certain examples, the RSPG is configured tore-invoke the REST API call until a threshold condition is met or untilthe response is received from the REST endpoint.

In certain examples, the RSPG is configured to determine that theresponse received from the REST endpoint indicates unavailability of theREST endpoint and responsive to the determining is configured tore-invoke the REST API call against the REST endpoint.

Various embodiments are described herein, including methods, systems,non-transitory computer-readable storage media storing programs, code,or instructions executable by one or more processors, and the like.These illustrative embodiments are mentioned not to limit or define thedisclosure, but to provide examples to aid understanding thereof.Additional embodiments are discussed in the Detailed Description, andfurther description is provided there.

BRIEF DESCRIPTION

Features, embodiments, and advantages of the present disclosure arebetter understood when the following Detailed Description is read withreference to the accompanying drawings.

FIG. 1 depicts a REST-SMTP protocol gateway that includes capabilitiesfor accessing and processing REST APIs using SMTP semantics, accordingto certain embodiments.

FIG. 2 depicts an example of a process performed by the RSPG foraccessing and processing REST APIs using SMTP semantics, according tocertain embodiments.

FIG. 3 depicts an example of a process implemented by the RSPG forre-invoking a REST API call against a REST endpoint, according tocertain embodiments.

FIG. 4 depicts an example of a process performed by the RSPG shown inFIG. 1 for extracting information related to a REST API call from one ormore data fields of an email message, according to certain embodiments.

FIG. 5 illustrates an example of an email message composed using RESTinformation, according to certain embodiments.

FIG. 6 is a block diagram illustrating an example pattern of an IaaSarchitecture, according to at least one embodiment,

FIG. 7 is a block diagram illustrating another example pattern of anIaaS architecture, according to at least one embodiment.

FIG. 8 is a block diagram illustrating another example pattern of anIaaS architecture, according to at least one embodiment.

FIG. 9 is a block diagram illustrating another example pattern of anIaaS architecture, according to at least one embodiment.

FIG. 10 illustrates an example computer system, in which variousembodiments may be implemented.

DETAILED DESCRIPTION

The present disclosure relates to techniques for accessing andprocessing REST APIs using SMTP. More particularly, the presentdisclosure relates to a REST-SMTP protocol gateway (RSPG) that includescapabilities for receiving an email message composed according to SMTPsemantics, converting the email message into a traditional REST API callfor execution at an endpoint, representing the results of execution ofthe REST API call using SMTP semantics and transmitting the results ofexecution to a sender or to alternative recipients of the email message.

In certain embodiments, the RSPG is implemented as a REST-aware SMTPrelay Message Transfer Agent (MTA) that is configured to receive, queueand process email messages according to a standard message deliveryprotocol (e.g., SMTP) used for communicating email messages to theirintended recipients. By way of example, the RSPG may represent a targetmail server (i.e., an MTA) responsible for accepting an email messagecomposed using an email client application and delivered via acloud-based email delivery service. The cloud-based email deliveryservice may represent an email message distribution network (EMDN) thatprovides a fast and reliable managed solution for sending a high-volumeof emails to be delivered to a set of intended recipients. The EMDN maycomprise a set of Message Transfer Agents (MTAs) that are configured toreceive email messages from various senders (e.g., tenants or customers)of the email delivery service and deliver the email messages to theirintended recipients.

In certain embodiments, the RSPG receives an email message from theEMDN, converts the email message composed using SMTP semantics into aHyper Text Transfer Protocol (HTTP) REST API call by extractinginformation from one or more data fields of the email message andconstructs a REST API call based on the extracted information. The RSPGthen invokes the REST API call against a local or remote REST endpointand obtains a result/response as a result of execution of the REST APIcall from the REST endpoint. The RSPG returns the response as an emailmessage to a user associated with the sender of the email message or toalternative recipients of the email message using SMTP semantics.

In certain examples, the response received from the REST endpoint mayindicate that the REST API call was successfully executed at theendpoint. In other examples, the response received from the RESTendpoint may indicate that the REST API call failed to executesuccessfully. In some examples, the response received from the RESTendpoint may indicate that the REST API call is still being executed andhas not yet completed execution at the endpoint. For instance, certainREST API operations (e.g., starting up a computing resource such as avirtual machine at the endpoint) may take a considerable amount of timeto complete execution at the endpoint. In such cases, the endpoint maybe configured to periodically return intermediate responses to the RSPG116 which may, in turn, transmit the responses asynchronously as emailmessages to the sender (or alternative recipient(s)) using SMTPsemantics. The intermediate response may include an intermediate resultvalue in the body of the email message that the user can use tosubsequently poll the endpoint for an update regarding the execution ofthe REST API call. For instance, the user may send a follow up emailmessage to obtain an update regarding the current status of execution ofthe REST API call using the intermediate result value. Thus, the RSPGdescribed in the present disclosure provides several technicaladvancements and/or improvements over conventional REST clients that donot traditionally support asynchronous calling mechanisms.

In certain embodiments, the RSPG may be configured with re-trycapabilities to automatically re-invoke a REST API call against a RESTendpoint when the RSPG does not receive a response from the endpointwithin a certain threshold period of time or if the RSPG receives anerror response from the endpoint indicating unavailability of theendpoint. By leveraging the native re-try capabilities provided by SMTPdelivery semantics, the RSPG is able to increase the reliability ofexecution of REST calls. After re-invoking the REST API call a certainnumber of times, if no response is received from the endpoint, the RSPGincludes capabilities to generate an email message indicating that noresponse was received and returns the email message to a user associatedwith the sender of the email message or to alternative recipients of theemail message using SMTP semantics.

The RSPG described in the present disclosure additionally providesseveral technical advancements and/or improvements over conventionalREST clients configured to execute REST API transactions against a RESTendpoint. For instance, in certain embodiments, the RSPG may beconfigured with capabilities to direct a REST API call to multipledifferent endpoints by extracting information identifying the differentendpoints from a data field (for e.g., a recipient field) of an emailmessage composed using standard email addressing semantics. The RSPG isthen configured to construct a REST API call directed to each endpointusing the extracted information and simultaneously deliver the REST APIcall to each of the target endpoints. Instead of a user having tocompose individual REST API calls directed to multiple differentendpoints using a traditional REST client, by using the new and improvedarchitecture provided by the RSPG, a user now needs to only compose asingle email message using SMTP semantics that is directed to multiplerecipients. The RSPG can then translate the email message intoindividual REST calls to be simultaneously delivered to the identifiedendpoints. This results in more efficient utilization of computingresources for performing REST transactions.

In addition, by using the RSPG described in the present disclosure, anemail message identifying REST related information that is composedusing SMTP semantics can be transmitted across multiple hops (e.g., viamultiple Relay MTAs) provided by an underlying message distributionnetwork (e.g., EMDN) without having to be encrypted or decrypted at eachhop, even if the SMTP message body is encrypted at one end. In contrast,a REST API call that is accessed using a traditional REST client thathas to go through multiple proxy servers (i.e., multiple hops) prior toreaching its destination has to be encrypted and decrypted at each hop.This requires the REST APIs typically to have extended HTTP usageheaders to include numerous custom headers and other functionality whichmakes leveraging the APIs directly from a REST client additionallychallenging.

Referring now to the drawings, FIG. 1 depicts a REST-SMTP protocolgateway that includes capabilities for accessing and processing RESTAPIs using SMTP semantics, according to certain embodiments. Thecomputing environment 100 may be implemented by one or more computingsystems that execute computer-readable instructions (e.g., code,program) to implement the computing environment 100. As depicted in FIG.1 , the computing environment 100 includes various systems andsubsystems including a source 102, an EMDN 110 and a REST-SMTP protocolgateway 116 (referred to herein as a RSPG). The systems and subsystemsdepicted in FIG. 1 may be implemented using software (e.g., code,instructions, program) executed by one or more processing units (e.g.,processors, cores) of a computing system, hardware, or combinationsthereof. The software may be stored on a non-transitory storage medium(e.g., on a memory device).

The computing environment 100 comprising the EMDN 110 and the RSPG 116may be implemented in various different configurations. In certainembodiments, the EMDN 110 and the RSPG 116 may be implemented on one ormore servers of a cloud provider network and their services forprocessing and executing REST API calls may be provided to subscribersof cloud services on a subscription basis. Computing environment 100depicted in FIG. 1 is merely an example and is not intended to undulylimit the scope of claimed embodiments. One of ordinary skill in the artwould recognize many possible variations, alternatives, andmodifications. For example, in some implementations, the EMDN 110 andthe RSPG-MTA 116 can be implemented using more or fewer subsystems thanthose shown in FIG. 1 , may combine two or more subsystems, or may havea different configuration or arrangement of subsystems.

In a certain implementation, the RSPG 116 represents a REST-aware SMTPrelay Message Transfer Agent (MTA) and is used as a target mail serverfor accepting email messages generated by an email client applicationand delivered using SMTP semantics provided by the EMDN 110. The RSPG116 receives an email message via the EMDN 102 and translates the emailmessage into a synchronous REST API call. The translation involvesextracting, by the RSPG 116, information from one or more data fields ofthe email message and constructing a REST API call based on theextracted information. The RSPG 116 invokes the REST API call against aREST API endpoint 120 and obtains a result/response as a result of theexecution of the REST API call from the REST endpoint. The RSPG 116 isthen configured to return the response as an email message reply to thesender of the email message or to alternative recipients of the emailmessage using standard SMTP semantics.

In the embodiment depicted in FIG. 1 , a first email message 106 withREST information may be generated by a source 102. The source 102 mayrepresent a system of an entity such as a customer or tenant (e.g., anorganization, an enterprise, or an individual) of the cloud serviceprovider who subscribes to the services provided by the EMDN 110 and theRSPG 116 for processing and executing REST API calls using SMTPsemantics. In certain examples, the source 102 may represent a system(i.e., a user device) that is communicatively coupled to the EMDN 110possibly via a public network (e.g., the Internet). The user device maybe of various types, including but not limited to, a mobile phone, atablet, a desktop computer, and the like. For instance, a user (e.g., anend user, a business owner, or a marketing officer associated with thesource 102) may interact with the EMDN 102 using a user interface (UI)(which may be a graphical user interface (GUI)) of an applicationexecuted by the user device. The application may be an email clientapplication 104 (e.g., a mail user agent (MUA)) installed in the deviceto enable the user to compose an email message. FIG. 5 illustrates anexample of an email message composed using REST information, accordingto certain embodiments. In certain examples, the mail user agent (MUA)may format the email message in a suitable format prior to submission tothe EMDN 110 and utilize a submission protocol (e.g., SMTP) to transmitthe message to the EMDN 102. In certain examples, the first emailmessage 106 may be automatically composed using software (e.g., code,instructions, program) implemented by the client application 104 withoutrequiring user interaction and the client application may be configuredto automatically send the first email message to the EMDN 102.

The first email message 106 is received by a local MTA 112 in the EMDN102 which then performs a Domain Name Server (DNS) Mail Exchanger (MX)record 108 resolution to identify the mail server (for e.g., a relayMTA-1 114 a) that is responsible for accepting email messages on behalfof the domain name of the recipient of the email message. The local MTA112 provides the email message via a message delivery protocol (e.g.,SMTP) to the indicated relay MTA (e.g., 114 a). The relay MTA 114 a hasno knowledge of any REST behavior, but just forwards the email messageas it would any other email message to another relay MTA (e.g., 114 b)which may then relay the email message along across several other relayMTA “hops” (any or all of which may be unaware of the eventual RSPG 116)to the RSPG 116 based on email routing rules at the destination MTAs.

The RSPG 116 may be configured to receive and queue email messagesaccording to the standard SMTP exchange protocol. For example, the RSPG116 may select an email message (e.g., the first email message 106)which may be stored at the head of its message queue for processing andextract information from one or more data fields of the first emailmessage. Based on the extracted information, the RSPG 116 thenconstructs a REST API call. In certain examples, the RSPG 116 may beconfigured to process the information in additional email headers of theemail message (if present) to handle factors such as userauthentication. The RSPG 116 then invokes the REST API call against alocal or remote REST API endpoint 120 and receives a response generatedfrom execution of the REST API call from the REST API endpoint. The RESTAPI endpoint 120 has no knowledge of any SMTP behavior, but justprocesses the REST API transaction as it would any other REST action andtransmits a response as a result of executing the REST API call to theRSPG 116. The RSPG 16 encapsulates the response/result into an emailmessage reply (i.e., a second email message 124 with the REST response),and forwards the response back to the intended recipients of the emailmessage. The response (i.e., in the form of an email message reply) fromthe REST exchange may be stored in a recipient system 126 for laterreview by the recipient or the response may be transmitted back to theuser associated with the source 102. The recipient system 126 mayrepresent an email service (inbox) provider (e.g., Gmail®, Yahoo®,Microsoft® and so on) of the recipient of the email message.

FIG. 2 depicts an example of a process 200 performed by the RSPG foraccessing and processing REST APIs using SMTP semantics, according tocertain embodiments. The processing depicted in FIG. 2 may beimplemented in software (e.g., code, instructions, program) executed byone or more processing units (e.g., processors, cores) of the respectivesystems, hardware, or combinations thereof. The software may be storedon a non-transitory storage medium (e.g., on a memory device). Theprocess 200 presented in FIG. 2 and described below is intended to beillustrative and non-limiting. Although FIG. 2 depicts the variousprocessing steps occurring in a particular sequence or order, this isnot intended to be limiting. In certain alternative embodiments, thesteps may be performed in some different order or some steps may also beperformed in parallel. In certain embodiments, such as in the embodimentdepicted in FIG. 1 , the processing depicted in FIG. 2 may be performedby the RSPG 116.

The processing depicted in FIG. 2 may be initiated when, at block 202,the RSPG 116 receives a first email message from the EMDN (e.g., from arelay MTA 114 n) and extracts information from the first email message.In certain examples, the processing at block 202 may include extracting,by the RSPG 116, information related to a REST API call from one or moredata fields of the first email message. Additional details of theprocessing performed by the RSPG 116 to extract information from thedata fields of the first email message is described in detail in FIG. 4.

At block 204, the RSPG 116 constructs a REST API call based on theinformation extracted in 202. For instance, based on the informationextracted from the data fields of the email message, the RSPG 116 mayconstruct a REST API call that comprises a “POST” action to create aresource at the endpoint.

At block 206, the RSPG 116 invokes the REST API call against a RESTendpoint 120. In certain examples the RSPG 116 is configured to invoke astandard HTTP REST API call to the specified REST endpoint based on theinformation extracted in block 202.

At block 208, the RSPG 116 receives a response generated from theexecution of the REST API call from the REST endpoint 120. In certainexamples, the response received from the REST endpoint may indicate thatthe REST API call was successfully executed at the endpoint. In thiscase, the response received from the REST endpoint may include aresponse status code (e.g., a HTTP standard response code 200)indicating that the REST API call was successfully executed and anactual result (for e.g., a resource accessed or created at the endpoint)based on execution of the REST API call. In certain examples, theresponse received from the REST endpoint may indicate that the REST APIcall failed to execute successfully. For instance, the REST API call mayfail to execute because of an error caused by the sender of the emailmessage while composing an email message comprising REST informationthat is to be translated into a REST API call by the RSPG 116. In thiscase, the response received from the REST endpoint may include aresponse status code (e.g., a HTTP standard response code 500)indicating that the REST API call failed to execute and an error messagegenerated from execution of the REST API call.

In certain embodiments, the response received from the REST endpoint mayindicate that the REST API call is still being executed and has not yetcompleted execution. For instance, certain operations (e.g., starting upa virtual machine at the endpoint) executed by a REST call may take aconsiderable amount of time to complete execution at the endpoint. Insuch cases, the RSPG 116 typically cannot keep a connection open to theendpoint until a response is obtained from the endpoint. In this case,the endpoint may be configured to periodically return an intermediateresponse status code (e.g., 201) comprising an intermediate resultacknowledging that the REST API call has been received for processingbut has not yet completed execution to the RSPG 116. The RSPG 116 may,in turn, transmit the intermediate responses asynchronously as emailmessages to the sender (or alternative recipient(s)) using SMTPsemantics. The intermediate response may include an intermediate resultvalue in the body of the email message that the user can use tosubsequently poll the endpoint for an update regarding the currentstatus of execution of the REST API call. For instance, the user maysend a follow up email message to obtain an update regarding theexecution of the REST API call using the intermediate result value.

At block 210, the RSPG 116 recomposes the information (i.e., responsecode and result) into an SMTP-compliant email (a second email messagedirected back to the sender (or an alternative supplied in the Reply Tofield).

At block 212, the RSPG 116 causes the second email message to becommunicated to an intended recipient of the response of the REST APIcall.

In certain embodiments, at block 208, the RSPG 116 may not receive aresponse from the REST endpoint (e.g., due to unavailability of theendpoint). In this case, the RSPG 116 may be configured to automaticallyre-invoke the REST API call against the endpoint a certain number oftimes until it receives a response back from the REST endpoint or untila threshold condition is satisfied. Thus, in certain implementations,the RSPG 116 may be configured with capabilities to increase thereliability of execution of REST calls by leveraging the nativere-trying capability provided by the underlying SMTP framework of theMTA to re-execute a REST API call multiple times until it receives aresponse back from the REST endpoint or until a threshold condition issatisfied.

FIG. 3 depicts an example of a process 300 implemented by the RSPG forre-invoking a REST API call against a REST endpoint, according tocertain embodiments. The processing depicted in FIG. 3 may beimplemented in software (e.g., code, instructions, program) executed byone or more processing units (e.g., processors, cores) of the respectivesystems, hardware, or combinations thereof. The software may be storedon a non-transitory storage medium (e.g., on a memory device). Theprocess 300 presented in FIG. 3 and described below is intended to beillustrative and non-limiting. Although FIG. 3 depicts the variousprocessing steps occurring in a particular sequence or order, this isnot intended to be limiting. In certain alternative embodiments, thesteps may be performed in some different order or some steps may also beperformed in parallel. In certain embodiments, such as in the embodimentdepicted in FIG. 1 , the processing depicted in FIG. 3 may be performedby the RSPG 116.

The processing depicted in blocks 302-306 in FIG. 3 is similar to theprocessing performed by the RSPG 116 in blocks 202-206 of FIG. 2 . Forinstance, at block 302, the RSPG 116 receives a first email message fromthe EMDN (e.g., from a relay MTA 114 n) and extracts information fromthe first email message. In certain examples, the processing at block302 may include extracting, by the RSPG 116, information related to aREST API call from one or more data fields of the first email message.At block 304, the RSPG 116 constructs a REST API call based on theinformation extracted in 302 and at block 306, the RSPG 116 invokes theREST API call against a REST endpoint 120.

At block 308, the RSPG 116 determines if the REST API call should bere-tried. For instance, the RSPG 116 may determine that the REST APIcall should be re-tried when the RSPG 116 does not get a response backfrom the endpoint within a certain threshold period of time or if theRSPG 116 or gets an error code back from the endpoint indicatingunavailability of the endpoint.

If the RSPG 116 determines that the REST API call should be re-tried,then, at block 310, the RSPG 116 determines if the number of re-trieshave exceeded a certain threshold value. The threshold value may beconfigured by a user of the RSPG 116 at the time of configuring the RSPG116 for accessing and processing REST API calls using SMTP semantics. Ifthe number of re-tries have not exceeded the threshold value, the RSPG116 automatically re-invokes the REST API call against the RESTendpoint. If the number of re-tries have exceeded the threshold value,then at block 312, the RSPG formulates a response indicating the resultof execution of the REST API call and at block 316 generates a secondemail message based on the response. For instance, the response may beformulated by the RSPG 116 into an SMTP-compliant email (a second emailmessage directed back to the sender (or an alternative recipientsupplied in the Reply To field) indicating that the REST API call couldnot be successfully executed.

If at block 308, the RSPG 116 determines that the REST API call wassuccessfully executed (i.e., it does not have to be re-tried), then, atblock 314, the RSPG receives a response generated from the execution ofthe REST API call from the REST endpoint and at block 216 and formulatesthe response into a second email message to be directed back to thesender, i.e., the intended recipient (or an alternative recipientsupplied in the Reply To field). At block 318, the RSPG causes thesecond email message to be communicated to an intended recipient of theresponse of the REST API call.

FIG. 4 depicts an example of a process 400 performed by the RSPG shownin FIG. 1 for extracting information related to a REST API call from oneor more data fields of an email message, according to certainembodiments. The processing depicted in FIG. 4 may be implemented insoftware (e.g., code, instructions, program) executed by one or moreprocessing units (e.g., processors, cores) of the respective systems,hardware, or combinations thereof. The software may be stored on anon-transitory storage medium (e.g., on a memory device). The process400 presented in FIG. 4 and described below is intended to beillustrative and non-limiting. Although FIG. 4 depicts the variousprocessing steps occurring in a particular sequence or order, this isnot intended to be limiting. In certain alternative embodiments, thesteps may be performed in some different order or some steps may also beperformed in parallel. In certain embodiments, the processing depictedin FIG. 4 may be performed by the RSPG 116 and depicts additionaldetails of the processing performed by the RSPG 116 in block 202 shownin FIG. 2 or in block 302 shown in FIG. 3 .

The processing depicted in FIG. 4 is described in relation to an exampleemail message that is composed by a user associated with the source 102and received for processing by the RSPG 116 from a relay MTA (e.g., 114n) in the EMDN 110. FIG. 5 illustrates an example of an email messagecomprising REST information, according to certain embodiments. In theexample shown in FIG. 5 , the email message comprises multiple fields,such as a “To” field that identifies the intended recipient of the emailmessage, a “Reply To” field 506 that identifies alternate recipients ofthe email message other than the “FROM” email address used by the senderto send the email message, the “Subject” field identifies the subject ofthe email message and the “Body” field identifies additional contents ofthe email message.

The processing depicted in FIG. 4 is initiated when the RSPG 116receives an email message (e.g., a first email message) for processing.At block 402, the RSPG 116 extracts information from the “To” field ofthe email message.

At block 404, from the information extracted from the “To” field of theemail message in 402, the RSPG 116 extracts information identifying theREST endpoint to call from the “Username” portion 502 of the “To” fieldof the email message. In the example shown in FIG. 5 , the “Username”portion of the “To” field is “arbitrary.rest.endpoint.com” andidentifies the REST endpoint to call.

At block 406, from the information extracted from the “To” field of theemail message in 402, the RSPG 116 extracts information identifying themail server (i.e., RSPG 116) for accepting the email message from the“Domain Name” portion 504 of the “To” field of the email message. Forexample, as shown in FIG. 5 , the “Domain Name” “rspg.business.org”identifies the RSPG for accepting the email message. The Domain Name(i.e., the hostname) portion is subject to traditional SMTP MX recordand MTA routing, through which the email message will eventually bedelivered to the RSPG MTA at which point the username portion of theemail will be processed by the RSPG-MTA to determine which REST endpointto call.

At block 408, the RSPG 116 extracts information from the “Subject” fieldof the email message. For the example shown in FIG. 5 , this informationmay include the REST action verb (e.g., POST) and a pathname (e.g.,service/item/12345/actions/foo) that uniquely identifies a resource tobe accessed by the REST API call at the REST endpoint.

At block 410, from the information extracted in 408, the RSPG 116extracts information identifying an “action” 508 to be performed by theREST API call. For the example shown in FIG. 5 , the action is a “POST”action used to create a resource as a result of execution of the RESTAPI call at the endpoint.

At block 412, from the information extracted in 408, the RSPG 116extracts information identifying a pathname 510 (e.g.,service/item/12345/actions/foo) that uniquely identifies a resource tobe accessed by the REST API call at the REST endpoint.

At block 414, the RSPG 116 extracts information from the body of theemail message. At block 416, from the information extracted in 414, theRSPG 116 extracts additional information 506 identifying the “action” tobe performed by the REST API call. For instance, in the example shown inFIG. 5 , the additional information may include a “key-value” pairassociated with the action to be performed. The key-value pairidentifies a key (which is a unique identifier for some item of data)and a value (which is either the data that is identified or a pointer tothe location of that data) associated with a resource to be accessed bythe REST API call at the REST endpoint. In certain examples, the body ofthe email message can be encrypted, and the RSPG 116 may be configuredto store the private key necessary to decrypt it (e.g. using Public KeyInfrastructure (PKI)). This allows for the secure relay of the encryptedbody REST contents and response, whereby the RSPG 116 is configured toencrypt the response using the public key for the destinationrecipients, using, for example, public key servers (tools) designed tosecure your communications and encrypt files (e.g., GPG Mail).

The RSPG described in the present disclosure additionally providesseveral technical advancements and/or improvements over conventionalREST clients configured to execute REST API transactions against a RESTendpoint. For instance, in certain embodiments, the RSPG may beconfigured with capabilities to direct a REST API call to multipledifferent endpoints by extracting information identifying the differentendpoints from a data field (for e.g., a recipient field) of an emailmessage composed using standard email addressing semantics. The RSPG isthen configured to construct a REST API call directed to each endpointusing the extracted information and simultaneously deliver the REST APIcall to each of the target endpoints. Instead of a user having tocompose individual REST API calls directed to multiple differentendpoints using a traditional REST client, by using the new and improvedarchitecture provided by the RSPG, a user now needs to only compose asingle email message using SMTP semantics that is directed to multiplerecipients. The RSPG can then translate the email message intoindividual REST calls to be simultaneously delivered to the identifiedendpoints. This results in more efficient utilization of resources forperforming REST transactions.

In addition, by using the RSPG described in the present disclosure, anemail message identifying REST related information that is composedusing SMTP semantics can be transmitted across multiple hops (e.g., viamultiple Relay MTAs) provided by an underlying message distributionnetwork (e.g., EMDN) without having to be encrypted or decrypted at eachhop, even if the SMTP message body is encrypted at one end. In contrast,a REST API call that is accessed using a traditional REST client thathas to go through multiple proxy servers (i.e., multiple hops) prior toreaching its destination has to be encrypted and decrypted at each hop.This requires the REST APIs typically to have extended HTTP usageheaders to include numerous custom headers and other functionality whichmakes leveraging the APIs directly from a REST client additionallychallenging.

The term cloud service is generally used to refer to a service that ismade available by a cloud services provider (CSP) to users or customerson demand (e.g., via a subscription model) using systems andinfrastructure (cloud infrastructure) provided by the CSP. Typically,the servers and systems that make up the CSP's infrastructure areseparate from the customer's own on premise servers and systems.Customers can thus avail themselves of cloud services provided by theCSP without having to purchase separate hardware and software resourcesfor the services. Cloud services are designed to provide a subscribingcustomer easy, scalable access to applications and computing resourceswithout the customer having to invest in procuring the infrastructurethat is used for providing the services.

There are several cloud service providers that offer various types ofcloud services. There are various different types or models of cloudservices including Software-as-a-Service (SaaS), Platform-as-a-Service(PaaS), Infrastructure-as-a-Service (IaaS), and others.

A customer can subscribe to one or more cloud services provided by aCSP. The customer can be any entity such as an individual, anorganization, an enterprise, and the like. When a customer subscribes toor registers for a service provided by a CSP, a tenancy or an account iscreated for that customer. The customer can then, via this account,access the subscribed-to one or more cloud resources associated with theaccount.

As noted above, infrastructure as a service (IaaS) is one particulartype of cloud computing. IaaS can be configured to provide virtualizedcomputing resources over a public network (e.g., the Internet). In anIaaS model, a cloud computing provider can host the infrastructurecomponents (e.g., servers, storage devices, network nodes (e.g.,hardware), deployment software, platform virtualization (e.g., ahypervisor layer), or the like). In some cases, an IaaS provider mayalso supply a variety of services to accompany those infrastructurecomponents (e.g., billing, monitoring, logging, load balancing andclustering, etc.). Thus, as these services may be policy-driven, IaaSusers may be able to implement policies to drive load balancing tomaintain application availability and performance.

In some instances, IaaS customers may access resources and servicesthrough a wide area network (WAN), such as the Internet, and can use thecloud provider's services to install the remaining elements of anapplication stack. For example, the user can log in to the IaaS platformto create virtual machines (VMs), install operating systems (OSs) oneach VM, deploy middleware such as databases, create storage buckets forworkloads and backups, and even install enterprise software into thatVM. Customers can then use the provider's services to perform variousfunctions, including balancing network traffic, troubleshootingapplication issues, monitoring performance, managing disaster recovery,etc.

In most cases, a cloud computing model will require the participation ofa cloud provider. The cloud provider may, but need not be, a third-partyservice that specializes in providing (e.g., offering, renting, selling)IaaS. An entity might also opt to deploy a private cloud, becoming itsown provider of infrastructure services.

In some examples, IaaS deployment is the process of putting a newapplication, or a new version of an application, onto a preparedapplication server or the like. It may also include the process ofpreparing the server (e.g., installing libraries, daemons, etc.). Thisis often managed by the cloud provider, below the hypervisor layer(e.g., the servers, storage, network hardware, and virtualization).Thus, the customer may be responsible for handling (OS), middleware,and/or application deployment (e.g., on self-service virtual machines(e.g., that can be spun up on demand) or the like.

In some examples, IaaS provisioning may refer to acquiring computers orvirtual hosts for use, and even installing needed libraries or serviceson them. In most cases, deployment does not include provisioning, andthe provisioning may need to be performed first.

In some cases, there are two different challenges for IaaS provisioning.First, there is the initial challenge of provisioning the initial set ofinfrastructure before anything is running. Second, there is thechallenge of evolving the existing infrastructure (e.g., adding newservices, changing services, removing services, etc.) once everythinghas been provisioned. In some cases, these two challenges may beaddressed by enabling the configuration of the infrastructure to bedefined declaratively. In other words, the infrastructure (e.g., whatcomponents are needed and how they interact) can be defined by one ormore configuration files. Thus, the overall topology of theinfrastructure (e.g., what resources depend on which, and how they eachwork together) can be described declaratively. In some instances, oncethe topology is defined, a workflow can be generated that creates and/ormanages the different components described in the configuration files.

In some examples, an infrastructure may have many interconnectedelements. For example, there may be one or more virtual private clouds(VPCs) (e.g., a potentially on-demand pool of configurable and/or sharedcomputing resources), also known as a core network. In some examples,there may also be one or more inbound/outbound traffic group rulesprovisioned to define how the inbound and/or outbound traffic of thenetwork will be set up and one or more virtual machines (VMs). Otherinfrastructure elements may also be provisioned, such as a loadbalancer, a database, or the like. As more and more infrastructureelements are desired and/or added, the infrastructure may incrementallyevolve.

In some instances, continuous deployment techniques may be employed toenable deployment of infrastructure code across various virtualcomputing environments. Additionally, the described techniques canenable infrastructure management within these environments. In someexamples, service teams can write code that is desired to be deployed toone or more, but often many, different production environments (e.g.,across various different geographic locations, sometimes spanning theentire world). However, in some examples, the infrastructure on whichthe code will be deployed must first be set up. In some instances, theprovisioning can be done manually, a provisioning tool may be utilizedto provision the resources, and/or deployment tools may be utilized todeploy the code once the infrastructure is provisioned.

FIG. 6 is a block diagram 600 illustrating an example pattern of an IaaSarchitecture, according to at least one embodiment. Service operators602 can be communicatively coupled to a secure host tenancy 604 that caninclude a virtual cloud network (VCN) 606 and a secure host subnet 608.In some examples, the service operators 602 may be using one or moreclient computing devices, which may be portable handheld devices (e.g.,an iPhone®, cellular telephone, an iPad®, computing tablet, a personaldigital assistant (PDA)) or wearable devices (e.g., a Google Glass® headmounted display), running software such as Microsoft Windows Mobile®,and/or a variety of mobile operating systems such as iOS, Windows Phone,Android, BlackBerry 8, Palm OS, and the like, and being Internet,e-mail, short message service (SMS), Blackberry®, or other communicationprotocol enabled. Alternatively, the client computing devices can begeneral purpose personal computers including, by way of example,personal computers and/or laptop computers running various versions ofMicrosoft Windows®, Apple Macintosh®, and/or Linux operating systems.The client computing devices can be workstation computers running any ofa variety of commercially-available UNIX® or UNIX-like operatingsystems, including without limitation the variety of GNU/Linux operatingsystems, such as for example, Google Chrome OS. Alternatively, or inaddition, client computing devices may be any other electronic device,such as a thin-client computer, an Internet-enabled gaming system (e.g.,a Microsoft Xbox gaming console with or without a Kinect® gesture inputdevice), and/or a personal messaging device, capable of communicatingover a network that can access the VCN 606 and/or the Internet.

The VCN 606 can include a local peering gateway (LPG) 610 that can becommunicatively coupled to a secure shell (SSH) VCN 612 via an LPG 610contained in the SSH VCN 612. The SSH VCN 612 can include an SSH subnet614, and the SSH VCN 612 can be communicatively coupled to a controlplane VCN 616 via the LPG 610 contained in the control plane VCN 616.Also, the SSH VCN 612 can be communicatively coupled to a data plane VCN618 via an LPG 610. The control plane VCN 616 and the data plane VCN 618can be contained in a service tenancy 619 that can be owned and/oroperated by the IaaS provider.

The control plane VCN 616 can include a control plane demilitarized zone(DMZ) tier 620 that acts as a perimeter network (e.g., portions of acorporate network between the corporate intranet and external networks).The DMZ-based servers may have restricted responsibilities and help keepbreaches contained. Additionally, the DMZ tier 620 can include one ormore load balancer (LB) subnet(s) 622, a control plane app tier 624 thatcan include app subnet(s) 626, a control plane data tier 628 that caninclude database (DB) subnet(s) 630 (e.g., frontend DB subnet(s) and/orbackend DB subnet(s)). The LB subnet(s) 622 contained in the controlplane DMZ tier 620 can be communicatively coupled to the app subnet(s)626 contained in the control plane app tier 624 and an Internet gateway634 that can be contained in the control plane VCN 616, and the appsubnet(s) 626 can be communicatively coupled to the DB subnet(s) 630contained in the control plane data tier 628 and a service gateway 636and a network address translation (NAT) gateway 638. The control planeVCN 616 can include the service gateway 636 and the NAT gateway 638.

The control plane VCN 616 can include a data plane mirror app tier 640that can include app subnet(s) 626. The app subnet(s) 626 contained inthe data plane mirror app tier 640 can include a virtual networkinterface controller (VNIC) 642 that can execute a compute instance 644.The compute instance 644 can communicatively couple the app subnet(s)626 of the data plane mirror app tier 640 to app subnet(s) 626 that canbe contained in a data plane app tier 646.

The data plane VCN 618 can include the data plane app tier 646, a dataplane DMZ tier 648, and a data plane data tier 650. The data plane DMZtier 648 can include LB subnet(s) 622 that can be communicativelycoupled to the app subnet(s) 626 of the data plane app tier 646 and theInternet gateway 634 of the data plane VCN 618. The app subnet(s) 626can be communicatively coupled to the service gateway 636 of the dataplane VCN 618 and the NAT gateway 638 of the data plane VCN 618. Thedata plane data tier 650 can also include the DB subnet(s) 630 that canbe communicatively coupled to the app subnet(s) 626 of the data planeapp tier 646.

The Internet gateway 634 of the control plane VCN 616 and of the dataplane VCN 618 can be communicatively coupled to a metadata managementservice 652 that can be communicatively coupled to public Internet 654.Public Internet 654 can be communicatively coupled to the NAT gateway638 of the control plane VCN 616 and of the data plane VCN 618. Theservice gateway 636 of the control plane VCN 616 and of the data planeVCN 618 can be communicatively couple to cloud services 656.

In some examples, the service gateway 636 of the control plane VCN 616or of the data plane VCN 618 can make application programming interface(API) calls to cloud services 656 without going through public Internet654. The API calls to cloud services 656 from the service gateway 636can be one-way: the service gateway 636 can make API calls to cloudservices 656, and cloud services 656 can send requested data to theservice gateway 636. But, cloud services 656 may not initiate API callsto the service gateway 636.

In some examples, the secure host tenancy 604 can be directly connectedto the service tenancy 619, which may be otherwise isolated. The securehost subnet 608 can communicate with the SSH subnet 614 through an LPG610 that may enable two-way communication over an otherwise isolatedsystem. Connecting the secure host subnet 608 to the SSH subnet 614 maygive the secure host subnet 608 access to other entities within theservice tenancy 619.

The control plane VCN 616 may allow users of the service tenancy 619 toset up or otherwise provision desired resources. Desired resourcesprovisioned in the control plane VCN 616 may be deployed or otherwiseused in the data plane VCN 618. In some examples, the control plane VCN616 can be isolated from the data plane VCN 618, and the data planemirror app tier 640 of the control plane VCN 616 can communicate withthe data plane app tier 646 of the data plane VCN 618 via VNICs 642 thatcan be contained in the data plane mirror app tier 640 and the dataplane app tier 646.

In some examples, users of the system, or customers, can make requests,for example create, read, update, or delete (CRUD) operations, throughpublic Internet 654 that can communicate the requests to the metadatamanagement service 652. The metadata management service 652 cancommunicate the request to the control plane VCN 616 through theInternet gateway 634. The request can be received by the LB subnet(s)622 contained in the control plane DMZ tier 620. The LB subnet(s) 622may determine that the request is valid, and in response to thisdetermination, the LB subnet(s) 622 can transmit the request to appsubnet(s) 626 contained in the control plane app tier 624. If therequest is validated and requires a call to public Internet 654, thecall to public Internet 654 may be transmitted to the NAT gateway 638that can make the call to public Internet 654. Memory that may bedesired to be stored by the request can be stored in the DB subnet(s)630.

In some examples, the data plane mirror app tier 640 can facilitatedirect communication between the control plane VCN 616 and the dataplane VCN 618. For example, changes, updates, or other suitablemodifications to configuration may be desired to be applied to theresources contained in the data plane VCN 618. Via a VNIC 642, thecontrol plane VCN 616 can directly communicate with, and can therebyexecute the changes, updates, or other suitable modifications toconfiguration to, resources contained in the data plane VCN 618.

In some embodiments, the control plane VCN 616 and the data plane VCN618 can be contained in the service tenancy 619. In this case, the user,or the customer, of the system may not own or operate either the controlplane VCN 616 or the data plane VCN 618. Instead, the IaaS provider mayown or operate the control plane VCN 616 and the data plane VCN 618,both of which may be contained in the service tenancy 619. Thisembodiment can enable isolation of networks that may prevent users orcustomers from interacting with other users', or other customers',resources. Also, this embodiment may allow users or customers of thesystem to store databases privately without needing to rely on publicInternet 654, which may not have a desired level of threat prevention,for storage.

In other embodiments, the LB subnet(s) 622 contained in the controlplane VCN 616 can be configured to receive a signal from the servicegateway 636. In this embodiment, the control plane VCN 616 and the dataplane VCN 618 may be configured to be called by a customer of the IaaSprovider without calling public Internet 654. Customers of the IaaSprovider may desire this embodiment since database(s) that the customersuse may be controlled by the IaaS provider and may be stored on theservice tenancy 619, which may be isolated from public Internet 654.

FIG. 7 is a block diagram 700 illustrating another example pattern of anIaaS architecture, according to at least one embodiment. Serviceoperators 702 (e.g. service operators 602 of FIG. 6 ) can becommunicatively coupled to a secure host tenancy 704 (e.g. the securehost tenancy 604 of FIG. 6 ) that can include a virtual cloud network(VCN) 706 (e.g. the VCN 606 of FIG. 6 ) and a secure host subnet 708(e.g. the secure host subnet 608 of FIG. 6 ). The VCN 706 can include alocal peering gateway (LPG) 710 (e.g. the LPG 610 of FIG. 6 ) that canbe communicatively coupled to a secure shell (SSH) VCN 712 (e.g. the SSHVCN 612 of FIG. 6 ) via an LPG 610 contained in the SSH VCN 712. The SSHVCN 712 can include an SSH subnet 714 (e.g. the SSH subnet 614 of FIG. 6), and the SSH VCN 712 can be communicatively coupled to a control planeVCN 716 (e.g. the control plane VCN 616 of FIG. 6 ) via an LPG 710contained in the control plane VCN 716. The control plane VCN 716 can becontained in a service tenancy 719 (e.g. the service tenancy 619 of FIG.6 ), and the data plane VCN 718 (e.g. the data plane VCN 618 of FIG. 6 )can be contained in a customer tenancy 721 that may be owned or operatedby users, or customers, of the system.

The control plane VCN 716 can include a control plane DMZ tier 720 (e.g.the control plane DMZ tier 620 of FIG. 6 ) that can include LB subnet(s)722 (e.g. LB subnet(s) 622 of FIG. 6 ), a control plane app tier 724(e.g. the control plane app tier 624 of FIG. 6 ) that can include appsubnet(s) 726 (e.g. app subnet(s) 626 of FIG. 6 ), a control plane datatier 728 (e.g. the control plane data tier 628 of FIG. 6 ) that caninclude database (DB) subnet(s) 730 (e.g. similar to DB subnet(s) 630 ofFIG. 6 ). The LB subnet(s) 722 contained in the control plane DMZ tier720 can be communicatively coupled to the app subnet(s) 726 contained inthe control plane app tier 724 and an Internet gateway 734 (e.g. theInternet gateway 634 of FIG. 6 ) that can be contained in the controlplane VCN 716, and the app subnet(s) 726 can be communicatively coupledto the DB subnet(s) 730 contained in the control plane data tier 728 anda service gateway 736 (e.g. the service gateway of FIG. 6 ) and anetwork address translation (NAT) gateway 738 (e.g. the NAT gateway 638of FIG. 6 ). The control plane VCN 716 can include the service gateway736 and the NAT gateway 738.

The control plane VCN 716 can include a data plane mirror app tier 740(e.g. the data plane mirror app tier 640 of FIG. 6 ) that can includeapp subnet(s) 726. The app subnet(s) 726 contained in the data planemirror app tier 740 can include a virtual network interface controller(VNIC) 742 (e.g. the VNIC of 642) that can execute a compute instance744 (e.g. similar to the compute instance 644 of FIG. 6 ). The computeinstance 744 can facilitate communication between the app subnet(s) 726of the data plane mirror app tier 740 and the app subnet(s) 726 that canbe contained in a data plane app tier 746 (e.g. the data plane app tier646 of FIG. 6 ) via the VNIC 742 contained in the data plane mirror apptier 740 and the VNIC 742 contained in the data plane app tier 746.

The Internet gateway 734 contained in the control plane VCN 716 can becommunicatively coupled to a metadata management service 752 (e.g. themetadata management service 652 of FIG. 6 ) that can be communicativelycoupled to public Internet 754 (e.g. public Internet 654 of FIG. 6 ).Public Internet 754 can be communicatively coupled to the NAT gateway738 contained in the control plane VCN 716. The service gateway 736contained in the control plane VCN 716 can be communicatively couple tocloud services 756 (e.g. cloud services 656 of FIG. 6 ).

In some examples, the data plane VCN 718 can be contained in thecustomer tenancy 721. In this case, the IaaS provider may provide thecontrol plane VCN 716 for each customer, and the IaaS provider may, foreach customer, set up a unique compute instance 744 that is contained inthe service tenancy 719. Each compute instance 744 may allowcommunication between the control plane VCN 716, contained in theservice tenancy 719, and the data plane VCN 718 that is contained in thecustomer tenancy 721. The compute instance 744 may allow resources, thatare provisioned in the control plane VCN 716 that is contained in theservice tenancy 719, to be deployed or otherwise used in the data planeVCN 718 that is contained in the customer tenancy 721.

In other examples, the customer of the IaaS provider may have databasesthat live in the customer tenancy 721. In this example, the controlplane VCN 716 can include the data plane mirror app tier 740 that caninclude app subnet(s) 726. The data plane mirror app tier 740 can residein the data plane VCN 718, but the data plane mirror app tier 740 maynot live in the data plane VCN 718. That is, the data plane mirror apptier 740 may have access to the customer tenancy 721, but the data planemirror app tier 740 may not exist in the data plane VCN 718 or be ownedor operated by the customer of the IaaS provider. The data plane mirrorapp tier 740 may be configured to make calls to the data plane VCN 718but may not be configured to make calls to any entity contained in thecontrol plane VCN 716. The customer may desire to deploy or otherwiseuse resources in the data plane VCN 718 that are provisioned in thecontrol plane VCN 716, and the data plane mirror app tier 740 canfacilitate the desired deployment, or other usage of resources, of thecustomer.

In some embodiments, the customer of the IaaS provider can apply filtersto the data plane VCN 718. In this embodiment, the customer candetermine what the data plane VCN 718 can access, and the customer mayrestrict access to public Internet 754 from the data plane VCN 718. TheIaaS provider may not be able to apply filters or otherwise controlaccess of the data plane VCN 718 to any outside networks or databases.Applying filters and controls by the customer onto the data plane VCN718, contained in the customer tenancy 721, can help isolate the dataplane VCN 718 from other customers and from public Internet 754.

In some embodiments, cloud services 756 can be called by the servicegateway 736 to access services that may not exist on public Internet754, on the control plane VCN 716, or on the data plane VCN 718. Theconnection between cloud services 756 and the control plane VCN 716 orthe data plane VCN 718 may not be live or continuous. Cloud services 756may exist on a different network owned or operated by the IaaS provider.Cloud services 756 may be configured to receive calls from the servicegateway 736 and may be configured to not receive calls from publicInternet 754. Some cloud services 756 may be isolated from other cloudservices 756, and the control plane VCN 716 may be isolated from cloudservices 756 that may not be in the same region as the control plane VCN716. For example, the control plane VCN 716 may be located in “Region1,” and cloud service “Deployment 6,” may be located in Region 1 and in“Region 2.” If a call to Deployment 6 is made by the service gateway 736contained in the control plane VCN 716 located in Region 1, the call maybe transmitted to Deployment 6 in Region 1. In this example, the controlplane VCN 716, or Deployment 6 in Region 1, may not be communicativelycoupled to, or otherwise in communication with, Deployment 6 in Region2.

FIG. 8 is a block diagram 800 illustrating another example pattern of anIaaS architecture, according to at least one embodiment. Serviceoperators 802 (e.g. service operators 602 of FIG. 6 ) can becommunicatively coupled to a secure host tenancy 804 (e.g. the securehost tenancy 604 of FIG. 6 ) that can include a virtual cloud network(VCN) 806 (e.g. the VCN 606 of FIG. 6 ) and a secure host subnet 808(e.g. the secure host subnet 608 of FIG. 6 ). The VCN 806 can include anLPG 810 (e.g. the LPG 610 of FIG. 6 ) that can be communicativelycoupled to an SSH VCN 812 (e.g. the SSH VCN 612 of FIG. 6 ) via an LPG810 contained in the SSH VCN 812. The SSH VCN 812 can include an SSHsubnet 814 (e.g. the SSH subnet 614 of FIG. 6 ), and the SSH VCN 812 canbe communicatively coupled to a control plane VCN 816 (e.g. the controlplane VCN 616 of FIG. 6 ) via an LPG 810 contained in the control planeVCN 816 and to a data plane VCN 818 (e.g. the data plane 618 of FIG. 6 )via an LPG 810 contained in the data plane VCN 818. The control planeVCN 816 and the data plane VCN 818 can be contained in a service tenancy819 (e.g. the service tenancy 619 of FIG. 6 ).

The control plane VCN 816 can include a control plane DMZ tier 820 (e.g.the control plane DMZ tier 620 of FIG. 6 ) that can include loadbalancer (LB) subnet(s) 822 (e.g. LB subnet(s) 622 of FIG. 6 ), acontrol plane app tier 824 (e.g. the control plane app tier 624 of FIG.6 ) that can include app subnet(s) 826 (e.g. similar to app subnet(s)626 of FIG. 6 ), a control plane data tier 828 (e.g. the control planedata tier 628 of FIG. 6 ) that can include DB subnet(s) 830. The LBsubnet(s) 822 contained in the control plane DMZ tier 820 can becommunicatively coupled to the app subnet(s) 826 contained in thecontrol plane app tier 824 and to an Internet gateway 834 (e.g. theInternet gateway 634 of FIG. 6 ) that can be contained in the controlplane VCN 816, and the app subnet(s) 826 can be communicatively coupledto the DB subnet(s) 830 contained in the control plane data tier 828 andto a service gateway 836 (e.g. the service gateway of FIG. 6 ) and anetwork address translation (NAT) gateway 838 (e.g. the NAT gateway 638of FIG. 6 ). The control plane VCN 816 can include the service gateway836 and the NAT gateway 838.

The data plane VCN 818 can include a data plane app tier 846 (e.g. thedata plane app tier 646 of FIG. 6 ), a data plane DMZ tier 848 (e.g. thedata plane DMZ tier 648 of FIG. 6 ), and a data plane data tier 850(e.g. the data plane data tier 650 of FIG. 6 ). The data plane DMZ tier848 can include LB subnet(s) 822 that can be communicatively coupled totrusted app subnet(s) 860 and untrusted app subnet(s) 862 of the dataplane app tier 846 and the Internet gateway 834 contained in the dataplane VCN 818. The trusted app subnet(s) 860 can be communicativelycoupled to the service gateway 836 contained in the data plane VCN 818,the NAT gateway 838 contained in the data plane VCN 818, and DBsubnet(s) 830 contained in the data plane data tier 850. The untrustedapp subnet(s) 862 can be communicatively coupled to the service gateway836 contained in the data plane VCN 818 and DB subnet(s) 830 containedin the data plane data tier 850. The data plane data tier 850 caninclude DB subnet(s) 830 that can be communicatively coupled to theservice gateway 836 contained in the data plane VCN 818.

The untrusted app subnet(s) 862 can include one or more primary VNICs864(1)-(N) that can be communicatively coupled to tenant virtualmachines (VMs) 866(1)-(N). Each tenant VM 866(1)-(N) can becommunicatively coupled to a respective app subnet 867(1)-(N) that canbe contained in respective container egress VCNs 868(1)-(N) that can becontained in respective customer tenancies 870(1)-(N). Respectivesecondary VNICs 872(1)-(N) can facilitate communication between theuntrusted app subnet(s) 862 contained in the data plane VCN 818 and theapp subnet contained in the container egress VCNs 868(1)-(N). Eachcontainer egress VCNs 868(1)-(N) can include a NAT gateway 838 that canbe communicatively coupled to public Internet 854 (e.g. public Internet654 of FIG. 6 ).

The Internet gateway 834 contained in the control plane VCN 816 andcontained in the data plane VCN 818 can be communicatively coupled to ametadata management service 852 (e.g. the metadata management system 652of FIG. 6 ) that can be communicatively coupled to public Internet 854.Public Internet 854 can be communicatively coupled to the NAT gateway838 contained in the control plane VCN 816 and contained in the dataplane VCN 818. The service gateway 836 contained in the control planeVCN 816 and contained in the data plane VCN 818 can be communicativelycouple to cloud services 856.

In some embodiments, the data plane VCN 818 can be integrated withcustomer tenancies 870. This integration can be useful or desirable forcustomers of the IaaS provider in some cases such as a case that maydesire support when executing code. The customer may provide code to runthat may be destructive, may communicate with other customer resources,or may otherwise cause undesirable effects. In response to this, theIaaS provider may determine whether to run code given to the IaaSprovider by the customer.

In some examples, the customer of the IaaS provider may grant temporarynetwork access to the IaaS provider and request a function to beattached to the data plane tier app 846. Code to run the function may beexecuted in the VMs 866(1)-(N), and the code may not be configured torun anywhere else on the data plane VCN 818. Each VM 866(1)-(N) may beconnected to one customer tenancy 870. Respective containers 871(1)-(N)contained in the VMs 866(1)-(N) may be configured to run the code. Inthis case, there can be a dual isolation (e.g., the containers871(1)-(N) running code, where the containers 871(1)-(N) may becontained in at least the VM 866(1)-(N) that are contained in theuntrusted app subnet(s) 862), which may help prevent incorrect orotherwise undesirable code from damaging the network of the IaaSprovider or from damaging a network of a different customer. Thecontainers 871(1)-(N) may be communicatively coupled to the customertenancy 870 and may be configured to transmit or receive data from thecustomer tenancy 870. The containers 871(1)-(N) may not be configured totransmit or receive data from any other entity in the data plane VCN818. Upon completion of running the code, the IaaS provider may kill orotherwise dispose of the containers 871(1)-(N).

In some embodiments, the trusted app subnet(s) 860 may run code that maybe owned or operated by the IaaS provider. In this embodiment, thetrusted app subnet(s) 860 may be communicatively coupled to the DBsubnet(s) 830 and be configured to execute CRUD operations in the DBsubnet(s) 830. The untrusted app subnet(s) 862 may be communicativelycoupled to the DB subnet(s) 830, but in this embodiment, the untrustedapp subnet(s) may be configured to execute read operations in the DBsubnet(s) 830. The containers 871(1)-(N) that can be contained in the VM866(1)-(N) of each customer and that may run code from the customer maynot be communicatively coupled with the DB subnet(s) 830.

In other embodiments, the control plane VCN 816 and the data plane VCN818 may not be directly communicatively coupled. In this embodiment,there may be no direct communication between the control plane VCN 816and the data plane VCN 818. However, communication can occur indirectlythrough at least one method. An LPG 810 may be established by the IaaSprovider that can facilitate communication between the control plane VCN816 and the data plane VCN 818. In another example, the control planeVCN 816 or the data plane VCN 818 can make a call to cloud services 856via the service gateway 836. For example, a call to cloud services 856from the control plane VCN 816 can include a request for a service thatcan communicate with the data plane VCN 818.

FIG. 9 is a block diagram 900 illustrating another example pattern of anIaaS architecture, according to at least one embodiment. Serviceoperators 902 (e.g. service operators 602 of FIG. 6 ) can becommunicatively coupled to a secure host tenancy 904 (e.g. the securehost tenancy 604 of FIG. 6 ) that can include a virtual cloud network(VCN) 906 (e.g. the VCN 606 of FIG. 6 ) and a secure host subnet 908(e.g. the secure host subnet 608 of FIG. 6 ). The VCN 906 can include anLPG 910 (e.g. the LPG 610 of FIG. 6 ) that can be communicativelycoupled to an SSH VCN 912 (e.g. the SSH VCN 612 of FIG. 6 ) via an LPG910 contained in the SSH VCN 912. The SSH VCN 912 can include an SSHsubnet 914 (e.g. the SSH subnet 614 of FIG. 6 ), and the SSH VCN 912 canbe communicatively coupled to a control plane VCN 916 (e.g. the controlplane VCN 616 of FIG. 6 ) via an LPG 910 contained in the control planeVCN 916 and to a data plane VCN 918 (e.g. the data plane 618 of FIG. 6 )via an LPG 910 contained in the data plane VCN 918. The control planeVCN 916 and the data plane VCN 918 can be contained in a service tenancy919 (e.g. the service tenancy 619 of FIG. 6 ).

The control plane VCN 916 can include a control plane DMZ tier 920 (e.g.the control plane DMZ tier 620 of FIG. 6 ) that can include LB subnet(s)922 (e.g. LB subnet(s) 622 of FIG. 6 ), a control plane app tier 924(e.g. the control plane app tier 624 of FIG. 6 ) that can include appsubnet(s) 926 (e.g. app subnet(s) 626 of FIG. 6 ), a control plane datatier 928 (e.g. the control plane data tier 628 of FIG. 6 ) that caninclude DB subnet(s) 930 (e.g. DB subnet(s) 830 of FIG. 8 ). The LBsubnet(s) 922 contained in the control plane DMZ tier 920 can becommunicatively coupled to the app subnet(s) 926 contained in thecontrol plane app tier 924 and to an Internet gateway 934 (e.g. theInternet gateway 634 of FIG. 6 ) that can be contained in the controlplane VCN 916, and the app subnet(s) 926 can be communicatively coupledto the DB subnet(s) 930 contained in the control plane data tier 928 andto a service gateway 936 (e.g. the service gateway of FIG. 6 ) and anetwork address translation (NAT) gateway 938 (e.g. the NAT gateway 638of FIG. 6 ). The control plane VCN 916 can include the service gateway936 and the NAT gateway 938.

The data plane VCN 918 can include a data plane app tier 946 (e.g. thedata plane app tier 646 of FIG. 6 ), a data plane DMZ tier 948 (e.g. thedata plane DMZ tier 648 of FIG. 6 ), and a data plane data tier 950(e.g. the data plane data tier 650 of FIG. 6 ). The data plane DMZ tier948 can include LB subnet(s) 922 that can be communicatively coupled totrusted app subnet(s) 960 (e.g. trusted app subnet(s) 860 of FIG. 8 )and untrusted app subnet(s) 962 (e.g. untrusted app subnet(s) 862 ofFIG. 8 ) of the data plane app tier 946 and the Internet gateway 934contained in the data plane VCN 918. The trusted app subnet(s) 960 canbe communicatively coupled to the service gateway 936 contained in thedata plane VCN 918, the NAT gateway 938 contained in the data plane VCN918, and DB subnet(s) 930 contained in the data plane data tier 950. Theuntrusted app subnet(s) 962 can be communicatively coupled to theservice gateway 936 contained in the data plane VCN 918 and DB subnet(s)930 contained in the data plane data tier 950. The data plane data tier950 can include DB subnet(s) 930 that can be communicatively coupled tothe service gateway 936 contained in the data plane VCN 918.

The untrusted app subnet(s) 962 can include primary VNICs 964(1)-(N)that can be communicatively coupled to tenant virtual machines (VMs)966(1)-(N) residing within the untrusted app subnet(s) 962. Each tenantVM 966(1)-(N) can run code in a respective container 967(1)-(N), and becommunicatively coupled to an app subnet 926 that can be contained in adata plane app tier 946 that can be contained in a container egress VCN968. Respective secondary VNICs 972(1)-(N) can facilitate communicationbetween the untrusted app subnet(s) 962 contained in the data plane VCN918 and the app subnet contained in the container egress VCN 968. Thecontainer egress VCN can include a NAT gateway 938 that can becommunicatively coupled to public Internet 954 (e.g. public Internet 654of FIG. 6 ).

The Internet gateway 934 contained in the control plane VCN 916 andcontained in the data plane VCN 918 can be communicatively coupled to ametadata management service 952 (e.g. the metadata management system 652of FIG. 6 ) that can be communicatively coupled to public Internet 954.Public Internet 954 can be communicatively coupled to the NAT gateway938 contained in the control plane VCN 916 and contained in the dataplane VCN 918. The service gateway 936 contained in the control planeVCN 916 and contained in the data plane VCN 918 can be communicativelycouple to cloud services 956.

In some examples, the pattern illustrated by the architecture of blockdiagram 900 of FIG. 9 may be considered an exception to the patternillustrated by the architecture of block diagram 800 of FIG. 8 and maybe desirable for a customer of the IaaS provider if the IaaS providercannot directly communicate with the customer (e.g., a disconnectedregion). The respective containers 967(1)-(N) that are contained in theVMs 966(1)-(N) for each customer can be accessed in real-time by thecustomer. The containers 967(1)-(N) may be configured to make calls torespective secondary VNICs 972(1)-(N) contained in app subnet(s) 926 ofthe data plane app tier 946 that can be contained in the containeregress VCN 968. The secondary VNICs 972(1)-(N) can transmit the calls tothe NAT gateway 938 that may transmit the calls to public Internet 954.In this example, the containers 967(1)-(N) that can be accessed inreal-time by the customer can be isolated from the control plane VCN 916and can be isolated from other entities contained in the data plane VCN918. The containers 967(1)-(N) may also be isolated from resources fromother customers.

In other examples, the customer can use the containers 967(1)-(N) tocall cloud services 956. In this example, the customer may run code inthe containers 967(1)-(N) that requests a service from cloud services956. The containers 967(1)-(N) can transmit this request to thesecondary VNICs 972(1)-(N) that can transmit the request to the NATgateway that can transmit the request to public Internet 954. PublicInternet 954 can transmit the request to LB subnet(s) 922 contained inthe control plane VCN 916 via the Internet gateway 934. In response todetermining the request is valid, the LB subnet(s) can transmit therequest to app subnet(s) 926 that can transmit the request to cloudservices 956 via the service gateway 936.

It should be appreciated that IaaS architectures 600, 700, 800, 900depicted in the figures may have other components than those depicted.Further, the embodiments shown in the figures are only some examples ofa cloud infrastructure system that may incorporate an embodiment of thedisclosure. In some other embodiments, the IaaS systems may have more orfewer components than shown in the figures, may combine two or morecomponents, or may have a different configuration or arrangement ofcomponents.

In certain embodiments, the IaaS systems described herein may include asuite of applications, middleware, and database service offerings thatare delivered to a customer in a self-service, subscription-based,elastically scalable, reliable, highly available, and secure manner. Anexample of such an IaaS system is the Oracle Cloud Infrastructure (OCI)provided by the present assignee.

FIG. 10 illustrates an example computer system 1000, in which variousembodiments may be implemented. The system 1000 may be used to implementany of the computer systems described above. As shown in the figure,computer system 1000 includes a processing unit 1004 that communicateswith a number of peripheral subsystems via a bus subsystem 1002. Theseperipheral subsystems may include a processing acceleration unit 1006,an I/O subsystem 1008, a storage subsystem 1018 and a communicationssubsystem 1024. Storage subsystem 1018 includes tangiblecomputer-readable storage media 1022 and a system memory 1010.

Bus subsystem 1002 provides a mechanism for letting the variouscomponents and subsystems of computer system 1000 communicate with eachother as intended. Although bus subsystem 1002 is shown schematically asa single bus, alternative embodiments of the bus subsystem may utilizemultiple buses. Bus subsystem 1002 may be any of several types of busstructures including a memory bus or memory controller, a peripheralbus, and a local bus using any of a variety of bus architectures. Forexample, such architectures may include an Industry StandardArchitecture (ISA) bus, Micro Channel Architecture (MCA) bus, EnhancedISA (EISA) bus, Video Electronics Standards Association (VESA) localbus, and Peripheral Component Interconnect (PCI) bus, which can beimplemented as a Mezzanine bus manufactured to the IEEE P1386.1standard.

Processing unit 1004, which can be implemented as one or more integratedcircuits (e.g., a conventional microprocessor or microcontroller),controls the operation of computer system 1000. One or more processorsmay be included in processing unit 1004. These processors may includesingle core or multicore processors. In certain embodiments, processingunit 1004 may be implemented as one or more independent processing units1032 and/or 1034 with single or multicore processors included in eachprocessing unit. In other embodiments, processing unit 1004 may also beimplemented as a quad-core processing unit formed by integrating twodual-core processors into a single chip.

In various embodiments, processing unit 1004 can execute a variety ofprograms in response to program code and can maintain multipleconcurrently executing programs or processes. At any given time, some orall of the program code to be executed can be resident in processor(s)1004 and/or in storage subsystem 1018. Through suitable programming,processor(s) 1004 can provide various functionalities described above.Computer system 1000 may additionally include a processing accelerationunit 1006, which can include a digital signal processor (DSP), aspecial-purpose processor, and/or the like.

I/O subsystem 1008 may include user interface input devices and userinterface output devices. User interface input devices may include akeyboard, pointing devices such as a mouse or trackball, a touchpad ortouch screen incorporated into a display, a scroll wheel, a click wheel,a dial, a button, a switch, a keypad, audio input devices with voicecommand recognition systems, microphones, and other types of inputdevices. User interface input devices may include, for example, motionsensing and/or gesture recognition devices such as the Microsoft Kinect®motion sensor that enables users to control and interact with an inputdevice, such as the Microsoft Xbox® 360 game controller, through anatural user interface using gestures and spoken commands. Userinterface input devices may also include eye gesture recognition devicessuch as the Google Glass® blink detector that detects eye activity(e.g., ‘blinking’ while taking pictures and/or making a menu selection)from users and transforms the eye gestures as input into an input device(e.g., Google Glass®). Additionally, user interface input devices mayinclude voice recognition sensing devices that enable users to interactwith voice recognition systems (e.g., Siri® navigator), through voicecommands.

User interface input devices may also include, without limitation, threedimensional (3D) mice, joysticks or pointing sticks, gamepads andgraphic tablets, and audio/visual devices such as speakers, digitalcameras, digital camcorders, portable media players, webcams, imagescanners, fingerprint scanners, barcode reader 3D scanners, 3D printers,laser rangefinders, and eye gaze tracking devices. Additionally, userinterface input devices may include, for example, medical imaging inputdevices such as computed tomography, magnetic resonance imaging,position emission tomography, medical ultrasonography devices. Userinterface input devices may also include, for example, audio inputdevices such as MIDI keyboards, digital musical instruments and thelike.

User interface output devices may include a display subsystem, indicatorlights, or non-visual displays such as audio output devices, etc. Thedisplay subsystem may be a cathode ray tube (CRT), a flat-panel device,such as that using a liquid crystal display (LCD) or plasma display, aprojection device, a touch screen, and the like. In general, use of theterm “output device” is intended to include all possible types ofdevices and mechanisms for outputting information from computer system1000 to a user or other computer. For example, user interface outputdevices may include, without limitation, a variety of display devicesthat visually convey text, graphics and audio/video information such asmonitors, printers, speakers, headphones, automotive navigation systems,plotters, voice output devices, and modems.

Computer system 1000 may comprise a storage subsystem 1018 thatcomprises software elements, shown as being currently located within asystem memory 1010. System memory 1010 may store program instructionsthat are loadable and executable on processing unit 1004, as well asdata generated during the execution of these programs.

Depending on the configuration and type of computer system 1000, systemmemory 1010 may be volatile (such as random access memory (RAM)) and/ornon-volatile (such as read-only memory (ROM), flash memory, etc.) TheRAM typically contains data and/or program modules that are immediatelyaccessible to and/or presently being operated and executed by processingunit 1004. In some implementations, system memory 1010 may includemultiple different types of memory, such as static random access memory(SRAM) or dynamic random access memory (DRAM). In some implementations,a basic input/output system (BIOS), containing the basic routines thathelp to transfer information between elements within computer system1000, such as during start-up, may typically be stored in the ROM. Byway of example, and not limitation, system memory 1010 also illustratesapplication programs 1012, which may include client applications, Webbrowsers, mid-tier applications, relational database management systems(RDBMS), etc., program data 1014, and an operating system 1016. By wayof example, operating system 1016 may include various versions ofMicrosoft Windows®, Apple Macintosh®, and/or Linux operating systems, avariety of commercially-available UNIX® or UNIX-like operating systems(including without limitation the variety of GNU/Linux operatingsystems, the Google Chrome® OS, and the like) and/or mobile operatingsystems such as iOS, Windows® Phone, Android® OS, BlackBerry® 10 OS, andPalm® OS operating systems.

Storage subsystem 1018 may also provide a tangible computer-readablestorage medium for storing the basic programming and data constructsthat provide the functionality of some embodiments. Software (programs,code modules, instructions) that when executed by a processor providethe functionality described above may be stored in storage subsystem1018. These software modules or instructions may be executed byprocessing unit 1004. Storage subsystem 1018 may also provide arepository for storing data used in accordance with the presentdisclosure.

Storage subsystem 1000 may also include a computer-readable storagemedia reader 1020 that can further be connected to computer-readablestorage media 1022. Together and, optionally, in combination with systemmemory 1010, computer-readable storage media 1022 may comprehensivelyrepresent remote, local, fixed, and/or removable storage devices plusstorage media for temporarily and/or more permanently containing,storing, transmitting, and retrieving computer-readable information.

Computer-readable storage media 1022 containing code, or portions ofcode, can also include any appropriate media known or used in the art,including storage media and communication media, such as but not limitedto, volatile and non-volatile, removable and non-removable mediaimplemented in any method or technology for storage and/or transmissionof information. This can include tangible computer-readable storagemedia such as RAM, ROM, electronically erasable programmable ROM(EEPROM), flash memory or other memory technology, CD-ROM, digitalversatile disk (DVD), or other optical storage, magnetic cassettes,magnetic tape, magnetic disk storage or other magnetic storage devices,or other tangible computer readable media. This can also includenontangible computer-readable media, such as data signals, datatransmissions, or any other medium which can be used to transmit thedesired information and which can be accessed by computing system 1000.

By way of example, computer-readable storage media 1022 may include ahard disk drive that reads from or writes to non-removable, nonvolatilemagnetic media, a magnetic disk drive that reads from or writes to aremovable, nonvolatile magnetic disk, and an optical disk drive thatreads from or writes to a removable, nonvolatile optical disk such as aCD ROM, DVD, and Blu-Ray® disk, or other optical media.Computer-readable storage media 1022 may include, but is not limited to,Zip® drives, flash memory cards, universal serial bus (USB) flashdrives, secure digital (SD) cards, DVD disks, digital video tape, andthe like. Computer-readable storage media 1022 may also include,solid-state drives (SSD) based on non-volatile memory such asflash-memory based SSDs, enterprise flash drives, solid state ROM, andthe like, SSDs based on volatile memory such as solid state RAM, dynamicRAM, static RAM, DRAM-based SSDs, magnetoresistive RAM (MRAM) SSDs, andhybrid SSDs that use a combination of DRAM and flash memory based SSDs.The disk drives and their associated computer-readable media may providenon-volatile storage of computer-readable instructions, data structures,program modules, and other data for computer system 1000.

Communications subsystem 1024 provides an interface to other computersystems and networks. Communications subsystem 1024 serves as aninterface for receiving data from and transmitting data to other systemsfrom computer system 1000. For example, communications subsystem 1024may enable computer system 1000 to connect to one or more devices viathe Internet. In some embodiments communications subsystem 1024 caninclude radio frequency (RF) transceiver components for accessingwireless voice and/or data networks (e.g., using cellular telephonetechnology, advanced data network technology, such as 3G, 4G or EDGE(enhanced data rates for global evolution), WiFi (IEEE 802.11 familystandards, or other mobile communication technologies, or anycombination thereof), global positioning system (GPS) receivercomponents, and/or other components. In some embodiments communicationssubsystem 1024 can provide wired network connectivity (e.g., Ethernet)in addition to or instead of a wireless interface.

In some embodiments, communications subsystem 1024 may also receiveinput communication in the form of structured and/or unstructured datafeeds 1026, event streams 1028, event updates 1030, and the like onbehalf of one or more users who may use computer system 1000.

By way of example, communications subsystem 1024 may be configured toreceive data feeds 1026 in real-time from users of social networksand/or other communication services such as Twitter® feeds, Facebook®updates, web feeds such as Rich Site Summary (RSS) feeds, and/orreal-time updates from one or more third party information sources.

Additionally, communications subsystem 1024 may also be configured toreceive data in the form of continuous data streams, which may includeevent streams 1028 of real-time events and/or event updates 1030, thatmay be continuous or unbounded in nature with no explicit end. Examplesof applications that generate continuous data may include, for example,sensor data applications, financial tickers, network performancemeasuring tools (e.g. network monitoring and traffic managementapplications), clickstream analysis tools, automobile trafficmonitoring, and the like.

Communications subsystem 1024 may also be configured to output thestructured and/or unstructured data feeds 1026, event streams 1028,event updates 1030, and the like to one or more databases that may be incommunication with one or more streaming data source computers coupledto computer system 1000.

Computer system 1000 can be one of various types, including a handheldportable device (e.g., an iPhone® cellular phone, an iPad® computingtablet, a PDA), a wearable device (e.g., a Google Glass® head mounteddisplay), a PC, a workstation, a mainframe, a kiosk, a server rack, orany other data processing system.

Due to the ever-changing nature of computers and networks, thedescription of computer system 1000 depicted in the figure is intendedonly as a specific example. Many other configurations having more orfewer components than the system depicted in the figure are possible.For example, customized hardware might also be used and/or particularelements might be implemented in hardware, firmware, software (includingapplets), or a combination. Further, connection to other computingdevices, such as network input/output devices, may be employed. Based onthe disclosure and teachings provided herein, a person of ordinary skillin the art will appreciate other ways and/or methods to implement thevarious embodiments.

Although specific embodiments have been described, variousmodifications, alterations, alternative constructions, and equivalentsare also encompassed within the scope of the disclosure. Embodiments arenot restricted to operation within certain specific data processingenvironments, but are free to operate within a plurality of dataprocessing environments. Additionally, although embodiments have beendescribed using a particular series of transactions and steps, it shouldbe apparent to those skilled in the art that the scope of the presentdisclosure is not limited to the described series of transactions andsteps. Various features and aspects of the above-described embodimentsmay be used individually or jointly.

Further, while embodiments have been described using a particularcombination of hardware and software, it should be recognized that othercombinations of hardware and software are also within the scope of thepresent disclosure. Embodiments may be implemented only in hardware, oronly in software, or using combinations thereof. The various processesdescribed herein can be implemented on the same processor or differentprocessors in any combination. Accordingly, where components or modulesare described as being configured to perform certain operations, suchconfiguration can be accomplished, e.g., by designing electroniccircuits to perform the operation, by programming programmableelectronic circuits (such as microprocessors) to perform the operation,or any combination thereof. Processes can communicate using a variety oftechniques including but not limited to conventional techniques forinter process communication, and different pairs of processes may usedifferent techniques, or the same pair of processes may use differenttechniques at different times.

The specification and drawings are, accordingly, to be regarded in anillustrative rather than a restrictive sense. It will, however, beevident that additions, subtractions, deletions, and other modificationsand changes may be made thereunto without departing from the broaderspirit and scope as set forth in the claims. Thus, although specificdisclosure embodiments have been described, these are not intended to belimiting. Various modifications and equivalents are within the scope ofthe following claims.

The use of the terms “a” and “an” and “the” and similar referents in thecontext of describing the disclosed embodiments (especially in thecontext of the following claims) are to be construed to cover both thesingular and the plural, unless otherwise indicated herein or clearlycontradicted by context. The terms “comprising,” “having,” “including,”and “containing” are to be construed as open-ended terms (i.e., meaning“including, but not limited to,”) unless otherwise noted. The term“connected” is to be construed as partly or wholly contained within,attached to, or joined together, even if there is something intervening.Recitation of ranges of values herein are merely intended to serve as ashorthand method of referring individually to each separate valuefalling within the range, unless otherwise indicated herein and eachseparate value is incorporated into the specification as if it wereindividually recited herein. All methods described herein can beperformed in any suitable order unless otherwise indicated herein orotherwise clearly contradicted by context. The use of any and allexamples, or exemplary language (e.g., “such as”) provided herein, isintended merely to better illuminate embodiments and does not pose alimitation on the scope of the disclosure unless otherwise claimed. Nolanguage in the specification should be construed as indicating anynon-claimed element as essential to the practice of the disclosure.

Disjunctive language such as the phrase “at least one of X, Y, or Z,”unless specifically stated otherwise, is intended to be understoodwithin the context as used in general to present that an item, term,etc., may be either X, Y, or Z, or any combination thereof (e.g., X, Y,and/or Z). Thus, such disjunctive language is not generally intended to,and should not, imply that certain embodiments require at least one ofX, at least one of Y, or at least one of Z to each be present.

Preferred embodiments of this disclosure are described herein, includingthe best mode known for carrying out the disclosure. Variations of thosepreferred embodiments may become apparent to those of ordinary skill inthe art upon reading the foregoing description. Those of ordinary skillshould be able to employ such variations as appropriate and thedisclosure may be practiced otherwise than as specifically describedherein. Accordingly, this disclosure includes all modifications andequivalents of the subject matter recited in the claims appended heretoas permitted by applicable law. Moreover, any combination of theabove-described elements in all possible variations thereof isencompassed by the disclosure unless otherwise indicated herein.

All references, including publications, patent applications, andpatents, cited herein are hereby incorporated by reference to the sameextent as if each reference were individually and specifically indicatedto be incorporated by reference and were set forth in its entiretyherein.

In the foregoing specification, aspects of the disclosure are describedwith reference to specific embodiments thereof, but those skilled in theart will recognize that the disclosure is not limited thereto. Variousfeatures and aspects of the above-described disclosure may be usedindividually or jointly. Further, embodiments can be utilized in anynumber of environments and applications beyond those described hereinwithout departing from the broader spirit and scope of thespecification. The specification and drawings are, accordingly, to beregarded as illustrative rather than restrictive.

What is claimed is:
 1. A method comprising: for a first email messagereceived by a Representational State Transfer (REST) Simple MessageTransfer Protocol (SMTP) Protocol Gateway (RSPG), extracting, by theRSPG, information from one or more data fields of the received firstemail message for constructing a REST Application Programing Interface(API) call; constructing, by the RSPG, the REST Application ProgrammingInterface (API) call based on the extracted information from the one ormore data fields of the first email message, wherein the constructingcomprises extracting first information from a first data field from theone or more data fields of the first email message, and using the firstinformation to construct a first portion of a plurality of portions ofthe REST API call, the first portion corresponding to the first datafield; invoking, by the RSPG, the REST API call against a REST endpoint;receiving, by the RSPG, a response generated from execution of the RESTAPI call; generating, by the RSPG, a second email message based on theresponse; and causing, by the RSPG, the second email message to becommunicated to an intended recipient of the response of the REST APIcall.
 2. The method of claim 1, wherein extracting, by the RSPG, thefirst information from the first data field of the first email messagecomprises extracting the first information from a To field of the firstemail message, wherein extracting the first information from the Tofield comprises: extracting, from a Username portion of the To field ofthe first email message, the first information identifying the firstportion of the REST API call, the first portion identifying the RESTendpoint of the REST API call; and extracting, from a Domain Nameportion of the To field of the first email message, the firstinformation identifying the first portion of the REST API call, thefirst portion identifying the RSPG for accepting the first emailmessage.
 3. The method of claim 1, further comprising extracting, by theRSPG, second information from a second data field from the one or moredata fields of the first email message, wherein extracting, by the RSPG,the second information from the second data field of the first emailmessage comprises extracting the second information from a Subject fieldof the first email message, wherein extracting the second informationfrom the Subject field comprises: extracting, from the Subject field,the second information identifying a second portion of the plurality ofportions of the REST API call, the second portion identifying an actionto be performed by the REST API call; extracting, from the Subjectfield, the second information identifying the second portion of the RESTAPI call, the second portion identifying a pathname that uniquelyidentifies a resource to be accessed by the REST API call at the RESTendpoint; and using the second information to construct the secondportion of the REST API call.
 4. The method of claim 1, furthercomprising: extracting, by the RSPG, third information from a third datafield from the one or more data fields of the first email message,wherein extracting, by the RSPG, the third information from the thirddata field of the first email message further comprises extracting thethird information from a body of the first email message, the thirdinformation identifying a third portion of the plurality of portions ofthe REST API call, the third portion identifying information associatedwith the action to be performed by the REST API call; and using thethird information to construct the third portion of the REST API call.5. The method of claim 1, wherein the response generated from executionof the REST API call comprises a response status code indicating thatthe REST API call was successfully executed by the REST endpoint.
 6. Themethod of claim 1, wherein the response generated from execution of theREST API call comprises a response status code indicating that the RESTAPI call failed to successfully execute at the REST endpoint.
 7. Themethod of claim 1, wherein the response generated from execution of theREST API call comprises an intermediate response status code indicatingthat the REST API call is still being processed.
 8. The method of claim1, further comprising: determining, by the RSPG, that the response wasnot received from execution of the REST API call by the REST endpointwithin a threshold period of time; and responsive to the determining,re-invoking, by the RSPG, the REST API call to the REST endpoint.
 9. Themethod of claim 8, further comprising re-invoking the REST API calluntil a threshold condition is met or until the response is receivedfrom the REST endpoint.
 10. The method of claim 1, further comprising:determining, by the RSPG, that the response received from the RESTendpoint indicates unavailability of the REST endpoint; and responsiveto the determining, re-invoking, by the RSPG, the REST API call againstthe REST endpoint.
 11. A Representational State Transfer (REST) SimpleMessage Transfer Protocol (SMTP) Protocol Gateway (RSPG) comprising: amemory; and one or more processors configured to perform processing, theprocessing comprising: for a first email message received by the RSPG,extracting, by the RSPG, information from one or more data fields of thereceived first email message for constructing a REST ApplicationPrograming Interface (API) call; constructing, by the RSPG, the RESTApplication Programming Interface (API) call based on the extractedinformation from the one or more data fields of the first email message,wherein the constructing comprises extracting first information from afirst data field from the one or more data fields of the first emailmessage, and using the first information to construct a first portion ofa plurality of portions of the REST API call, the first portioncorresponding to the first data field; invoking, by the RSPG, the RESTAPI call against a REST endpoint; receiving, by the RSPG, a responsegenerated from execution of the REST API call; generating, by the RSPG,a second email message based on the response; and causing, by the RSPG,the second email message to be communicated to an intended recipient ofthe response of the REST API call.
 12. The system of claim 11, whereinextracting, by the RSPG, the first information from the first data fieldof the first email message comprises extracting the first informationfrom a To field of the first email message, wherein extracting the firstinformation from the To field comprises: extracting, from a Usernameportion of the To field of the first email message, the firstinformation identifying the first portion of the REST API call, thefirst portion identifying the REST endpoint of the REST API call; andextracting, from a Domain Name portion of the To field of the firstemail message, the first information identifying the first portion ofthe REST API call, the first portion identifying the RSPG for acceptingthe first email message.
 13. The system of claim 11, further comprisingextracting, by the RSPG, second information from a second data fieldfrom the one or more data fields of the first email message, whereinextracting, by the RSPG, the second information from the second datafield of the first email message comprises extracting the secondinformation from a Subject field of the first email message, whereinextracting the second information from the Subject field comprises:extracting, from the Subject field, the second information identifying asecond portion of the plurality of portions of the REST API call, thesecond portion identifying an action to be performed by the REST APIcall; extracting, from the Subject field, the second informationidentifying the second portion of the REST API call, the second portionidentifying a pathname that uniquely identifies a resource to beaccessed by the REST API call at the REST endpoint; and using the secondinformation to construct the second portion of the REST API call. 14.The system of claim 11, further comprising: extracting, by the RSPG,third information from a third data field from the one or more datafields of the first email message, wherein extracting, by the RSPG, thethird information from the third data field of the first email messagefurther comprises extracting the third information from a body of thefirst email message, the third information identifying a third portionof the plurality of portions of the REST API call, the third portionidentifying information associated with the action to be performed bythe REST API call; and using the third information to construct thethird portion of the REST API call.
 15. The system of claim 11, whereinthe response generated from execution of the REST API call comprises aresponse status code indicating that the REST API call was successfullyexecuted by the REST endpoint.
 16. The system of claim 11, furthercomprising: determining, by the RSPG, that the response was not receivedfrom execution of the REST API call by the REST endpoint within athreshold period of time; and responsive to the determining,re-invoking, by the RSPG, the REST API call to the REST endpoint. 17.The system of claim 16, further comprising re-invoking the REST API calluntil a threshold condition is met or until the response is receivedfrom the REST endpoint.
 18. A non-transitory computer-readable mediumhaving program code that is stored thereon, the program code executableby one or more processing devices for performing operations comprising:for a first email message received by a Representational State Transfer(REST) Simple Message Transfer Protocol (SMTP) Protocol Gateway (RSPG),extracting, by the RSPG, information from one or more data fields of thereceived first email message for constructing a REST ApplicationPrograming Interface (API) call; constructing, by the RSPG, RESTApplication Programming Interface (API) call based on the extractedinformation from the one or more data fields of the first email message,wherein the constructing comprises extracting first information from afirst data field from the one or more data fields of the first emailmessage, and using the first information to construct a first portion ofa plurality of portions of the REST API call, the first portioncorresponding to the first data field; invoking, by the RSPG, the RESTAPI call against a REST endpoint; receiving, by the RSPG, a responsegenerated from execution of the REST API call; generating, by the RSPG,a second email message based on the response; and causing, by the RSPG,the second email message to be communicated to an intended recipient ofthe response of the REST API call.
 19. The non-transitorycomputer-readable medium of claim 18, wherein extracting, by the RSPG,the first information from the first data field of the first emailmessage comprises extracting the first information from a To field ofthe first email message, wherein extracting the first information fromthe To field comprises: extracting, from a Username portion of the Tofield of the first email message, the first information identifying thefirst portion of the REST API call, the first portion identifying theREST endpoint of the REST API call; and extracting, from a Domain Nameportion of the To field of the first email message, the firstinformation identifying the first portion of the REST API call, thefirst portion identifying the RSPG for accepting the first emailmessage.
 20. The non-transitory computer-readable medium of claim 18,wherein the response generated from execution of the REST API callcomprises an intermediate response status code indicating that the RESTAPI call is still being processed.